A trend to emerge over the last decade in fashion eyewear and as means to protect a wearer from sunlight has been the advent of a “clip-on” sunglass. Clip-on sunglasses typically consist of auxiliary lenses with clip-like appearances that fit about the frames of the eyeglasses for attaching to eyeglasses such as prescription glasses. The clip-ons may be tinted or otherwise treated and are designed to match indoor prescription eyewear. Traditionally some frame manufacturers have offered clip-ons as an extra accessory, but not all eyeglass frames have corresponding clip-ons. When available the clip-on could be specially ordered for the customer or could be purchased as a set with the frames.
Alternatively, aftermarket clip-ons are available, including slip-ins, flip-ups, fit-overs, fit-behinds, and many variations. Some of these sun clips offer a one-size-fits-all option while others attempt to achieve a better fit by offering several different pre-made shapes to allow the wearer to choose a shape that closely matches the existing frames. Still other alternatives offer a lens grinding and assembly “laboratory service” to produce a customized after-market clip in which the sun lenses themselves are shaped the same as the prescription lenses.
Traditional clips typically have an eye wire or metal ring or rim that encircles the sunglass lenses about the circumference, a browbar that joins each lens together at the eye wire, a connection between the eye wire and browbar, and a connection of appendages to the eye wire. The appendages attach the clip-on lenses to the primary lenses of the prescriptive eyewear, or hold magnets to assist with attachment of the clip-on to the prescriptive lenses. These are constructed using a “browbar” having small “finger-like” appendages to grip the frame of the primary lenses to connect two sun lenses thereto at the circumference. Typically, both hands are required to attach traditional clip-ons to the eyeglass frames.
Magnetic-assisted clips offer another option for attaching clip-on lenses to eyeglasses. Magnetic clip-ons are often bundled with eyeglasses and sold as a set. Some magnetic sun clip-ons rely on appendages to which a small magnet is attached and attracts to a magnet attached on the eyewear frame. When clipped, the appendages overlap and magnetic attraction holds the two pieces together. Other magnetic sun lenses use magnets attached directly to magnets on or in the front face of the eyeglass frame or other parts comprising the frame.
While these designs offer certain advantages in the market, they have certain problems and shortcomings. Eye wires and appendages that attach traditional clip-ons to the eyeglasses add weight to the eyeglasses that can restrict the wearer's movement. Sometimes this weight is enough to cause the clip-on to detach unintentionally.
Further, appendages can potentially scratch the primary lenses when the clip-on is being attached to the primary lenses, such as when the appendages are improperly aligned. In general, clip-ons must be attached to the primary lens at a particular angle-of-attachment, such as by bringing the clip-on to mount bottom side first or top side first. Where clip-ons are attached by magnets, any bending, warping, or misshaping of the clip-on can cause alignment to be lost and detachment to occur. Often, even a slight disfigurement to the eyeglasses, even such as results from normal wear and tear, may cause the clip-on and eyeglasses to lose their symmetry such that the clip-on might not attach at all or only very weakly.
Another limitation of these conventional clip-ons is that they are not aesthetically pleasing to some consumers. They often lack the fine design and construction of some of the more upscale hand-made frames that are available on the market today. Fewer choices are available compared to the vast array of optical frames.
Yet another problem with conventional clip-ons is that they have a tendency to break. For example, the eye wire, browbar, and/or prongs tend to lack durability. This is often problematic because wearers tend to subject these products to a high degree of wear and tear.
Accordingly, there is a need for a supplemental lens that accommodates a variety of eyeglasses, is light weight and less likely to scratch or detach, provides stability, and/or can be customized.